Mullite vs. Aluminum Nitride
Mullite belongs to the oxide-based engineering ceramics classification, while aluminum nitride belongs to the non-oxide engineering ceramics. There are 19 material properties with values for both materials. Properties with values for just one material (6, in this case) are not shown.
For each property being compared, the top bar is mullite and the bottom bar is aluminum nitride.
Metric UnitsUS Customary Units
Mechanical Properties
| Compressive (Crushing) Strength, MPa | 800 | |
| 2100 |
| Elastic (Young's, Tensile) Modulus, GPa | 110 to 170 | |
| 330 |
| Flexural Strength, MPa | 130 to 160 | |
| 190 to 400 |
| Fracture Toughness, MPa-m1/2 | 2.0 | |
| 2.9 |
| Knoop Hardness | 750 | |
| 1160 |
| Poisson's Ratio | 0.25 | |
| 0.21 to 0.31 |
Thermal Properties
| Maximum Temperature: Mechanical, °C | 1680 | |
| 1380 |
| Maximum Thermal Shock, °C | 170 to 230 | |
| 220 |
| Specific Heat Capacity, J/kg-K | 950 | |
| 780 |
| Thermal Conductivity, W/m-K | 3.5 to 11 | |
| 80 to 190 |
| Thermal Expansion, µm/m-K | 5.8 | |
| 4.2 to 5.4 |
Electrical Properties
| Dielectric Constant (Relative Permittivity) At 1 MHz | 6.3 | |
| 6.9 to 28 |
| Dielectric Strength (Breakdown Potential), kV/mm | 16 to 17 | |
| 15 to 56 |
| Electrical Dissipation At 1 MHz | 0.0025 | |
| 0.00020 to 0.0010 |
| Electrical Resistivity Order of Magnitude, 10x Ω-m | 10 to 11 | |
| 10 to 12 |
Otherwise Unclassified Properties
| Density, g/cm3 | 2.7 to 3.0 | |
| 2.9 to 3.3 |
Common Calculations
| Stiffness to Weight: Axial, points | 22 to 31 | |
| 55 to 63 |
| Stiffness to Weight: Bending, points | 58 to 62 | |
| 69 to 80 |
| Thermal Diffusivity, mm2/s | 1.4 to 3.7 | |
| 31 to 74 |